It is an HP-41C/CV MicroCode Emulator for HP-48S/SX/G/G+/GX and HP-49G calculators.
The famous HP-41C/CV vintage calculators are fully recreated because I emulated
the real CPU behavior and the emulator executes a code from the real HP-41C/CV ROMs.
Recently, I decided to revive this emulator (developed and maintained from 1998. until 2000.)
using some code from HP-41X and HP-1XE to give it a fresh look.
Some features (like partially working Helios Printer and Phineas Clock Chip, MLDL, ZENROM,
CCD ROM and full CX support, etc.) were removed because they are fully implemented in HP-41X.
HP-41E doesn't compete with HP-41X because it's purpose is to be used as low-end emulator
by users who don't need advanced HP-41X capabilities.

Introduction

This is true microcode emulator of the HP-41C/CV/CX calculator. It emulates all
instructions of the famous Nut CPU (CocoNut, HalfNut, HoneyNut, ...), standard
and synthetical programming, display (all characters and punctuation) and
keyboard behavior (Press -> Command -> NULL), various relevant hardware, etc,
etc. Display is emulated without any flickering and keyboard reactions are
immediate. It even emulates auto turn-off feature and BEEP/TONE commands.
On my HP-48G+/GX/49G it is about 70-90% faster than real one (depending on the
application). On the old HP-48SX it is about 10-30% faster.

The following versions of the emulator are available:

HP41E: Basic HP-41C version with 64 registers
HP41EL: Lite HP-41C version with 64 registers (for HP-48S/G)
HP41EV: HP-41CV version with 320 registers
HP41EM: HP-41CV version with Math Module
HP41EF: HP-41CV version with Math and Finance Modules
HP41EP: HP-41CV version with PPC and Math Modules
HP41EX: HP-41CV version with XF/XM, PPC and Math Modules
HP41EA: HP-41CV version with XF/XM, PPC and Advantage Modules

Lite version is provided for the owners of HP-48S/G with 32K RAM and differs
from its big brothers in the following: (1) It is about 35% slower, (2) Only 64
registers for data and programs (like the basic HP-41C), (3) Much 'uglier' font,
(4) Special characters cannot have punctuation, (5) No Enhanced and Temporary Alpha Mode,
(6) No auto turn-off emulation, (7) No cold start, (8) No RAM loading/saving,
(9) ON&key combinations are not available. There are also few less important
differences.

Installation:

Just send the appropriate HP41Ex file (extracted from the ZIP distribution package) from the
computer to the calculator, store it to a variable and run the emulator. No additional steps are
required. On HP-48S/G calculators with 32K RAM only HP41EL version can be installed.

In the Enhanced Alpha Mode keys A..Z of the emulator correspond to keys A..Z
of the standard HP-48 Alpha keyboard. This makes character input very simple
and fast, especially for sequences like XEQ ALPHA something ALPHA. Other keys
(0..9,.,+,-,*,/,R/S) are unchanged (it means also that you enter numbers with
SHIFT like on the real one).

Similar to Enhanced Alpha Mode is Temporary Alpha Mode which can be activated
by ON&Alpha combination. This mode is very helpfull when keying commands like
RCL Y, STO Z, etc. because keys act like the emulator is in the Alpha mode
even if it is outside the Alpha mode. Temporary Alpha Mode is usually active
for the next keystroke only.

Note: HP-41E does not compete with HP-41X. For this reason, it is limited in features
and only limited number of modules is supported. I will not support additional modules
(like CCD ROM or HEPAX, for example) and additional hardware: Printer, Timer Chip, HPIL, ...
If you need them, you have to purchase HP-41X.

Program loading/saving

As HP-41E doesn't support Card Reader or HP-IL, it is not possible to load and save programs.
But, you can download RAW41.EXE program which provides limited RM41
loading/saving capabilities. RAW41 is described here.